Etiology of Acute Gastroenteritis in Three Sentinel General Practices, Austria 2007

We studied the etiology of acute gastroenteritis in a village with a total population of approximately 6,000. This is the first study in Austria that has investigated a broad range of pathogens recovered from an unselected population of patients who had consulted general practitioners because of gastroenteritis. In 2007, all patients who visited one of three local general practitioners for acute gastroenteritis were invited to provide stool specimens to be tested for Salmonella, Shigella, Campylobacter, enterohemorrhagic Escherichia coli (EHEC) (mTSB enrichment [R-Biopharm] followed by toxin ELISA plus culture), enteropathogenic E. coli (EPEC), Yersinia, Vibrio cholerae, Clostridium difficile (toxin plus culture), rotavirus plus adenovirus (RIDA(A (R)) Quick Rotavirus/Adenovirus Combi test), Giardia duodenalis plus Cryptosporidium parvum (RIDA(A (R)) Quick Cryptosporidium/Giardia Combi test), astrovirus (ELISA), and norovirus (reverse-transcriptase PCR). Stool specimens were provided by 306 patients (161 female) with acute diarrhea. The ages of the patients ranged from 1 to 89 years (mean 37, median 36). Pathogens were detected in 71 (23.2%) patients, with incidence peaks in February and June. Norovirus accounted for 36.0% of positive results, C. difficile for 18.7%, rotavirus for 17.3%, Campylobacter for 9.3%, Salmonella for 6.6%, adenovirus for 5.4%, G. duodenalis and C. parvum for 2.7% each, and Yersinia enterocolitica for 1.3%. No cases of shigellosis or infection with EHEC, EPEC, or astrovirus were diagnosed. Viruses accounted for 58.7% of the 75 positive results, bacteria for 36.0%, and parasites for 5.3%. Our study underlines a dominant role of norovirus and toxigenic C. difficile as etiologic agents of acute gastroenteritis among the patients of general practitioners.